Automatic jump rope



Nov. 3, 1959 B. L. WOLFSON 2,911,063

AUTOMATIC JUMP ROPE Filed May 21, 1958 I 2 Sheets-Sheet 1 INVENTOR Ema/vL. WoL Fs0/v y M W) ATTORNEY Noy. 3, 1959 B. L. WOLFSON 2,911,063

AUTOMATIC JUMP ROPE Filed May 21, 1958 2 Sheets-Sheet 2 Ema/v L. W01.FSON BY v %M ATTORNEY United States Patent .-The present inventionrelates generally to mechanisms for rotatin'g elongated flexiblematerial and more particularly to an .apparatus for rotating one end ofa jump rope, the other end of which is secured to a suitable support.

Briefly describing the general concept ofthe invention,

an. elongated shaft is rotatably supported in a generally.

horizontal position by two bearing structures attached to a. stationaryframe. Disposed on one end .of-the shaft, externally of theframe, is aweighted arm which is generally perpendicular to the shaft. A rope'isadapted to bezattached to the end of this arm and a source of motorpower is secured to the shaft to produce rotation thereof. The weightedarm is employed to reduce the angular velocity of the arm on its upwardmovement, thereby to simulate the movement of a jump rope when itispropelled by-human means.

The-apparatus forrotating the shaft may take. several forms. and inonespecificembodiment of the invention comprises two spiral springsdisposed about the shaft and each having one end secured to the shaftand the other end secured. to the frame. The convolutions of the springsare oppositely directed so that when one spring is wound,

onan end of the shaft, opposite to the end to which the arm-isattached,and initially the crank is operated so that one of the-spiral springs iswound and the other is unwound. Upon releasing the handle, the shaftrotates in one direction, for example for twenty turns, and then rotatesbackin the opposite direction for approximately nineteen turns. Theoscillatory movement of thelshaft therefore conforms to that of a dampedoscillatory body and themechanism may continue to oscillate back andforth, for aconsiderable length of time, for example, fifteen to twentyminutes.

- Such an apparatus may be employed by a child who wishes; to jump ropeand does not have a playmate availableufor. rotating the rope. The ropehas one end attachedto a suitable stationary object and the other endattached to the-end of the weighted arm and the mechanism of theinvention is displaced by a suitablev distance from the stationarymember so as to provide a loop which just barelydrags the, ground. Theapparatus is then cranked and released, .providing a continuing. motion.Smaller children may not wish to have a rope which is continuallyrotating in the same direction, but may. wish merely-to have a ropewhich oscillates to say. 180 at a relatively slow pace, so that a childmay jump each time the rope passes in either direction under the child.The apparatus of the present-invention may be readilymodified, .toprovide either effect, by either of two arrangements. In a firstarrangement a straight leaf spring is secured to the shaft and suitablestops are secured to the frame tointercept the free end of the leafspring at spaced points about its path of rotation. The apparatus maybeinitially-cranked so that the end of. the leaf spring engagesoireof thestops and is tensioned thereby, and their the apparatusis released. Bysuitably choosing the ice natural period of oscillation of the weightedarm and of the spring,=theoscillations of the arm maybe sustained fora-considerable period of time. In a modification of this latterembodiment of the invention, two oppositely directed spiral springs maybe employed in conjunction withthe leafspring in'order to provide asustained spring force on the shaft in the interval between movement ofthe free end of the leaf spring between the stops.

It is, accordingly, a broad object of the present invention to provide amechanism for rotating a jump rope which will simulate the motion of ajump rope when propelled by human means.

It is another object of the present invention to provide a mechanism forrotating a jump rope which produces sustained oscillation of the ropeover a relatively long period of time.

It is yet another object of the present invention to provide a mechanismfor rotating a jump rope which is spring actuated and which may-rotatethe rope first in one direction and then in another direction for asustained period of time.

' wherein;

Figure 1 is a perspective view of one embodiment of the presentinvention;

Figure 2 is a cross-sectional view of a side elevation of the firstembodiment of the apparatus of the present invention;

the other onezis unwound. A crank handle is disposed Figure 3' is adetailed view of the spring motor of the first embodiment of theapparatus of the invention;

Figure 4 is a detailed view of the method of connectirig the motorsprings to the frame of the first embodiment of the invention;

Figure 5 is a second detailed view of the spring motor of the firstembodiment of the invention; 1

Figure 6 is a detailed view of the spring motor of a second embodimentof the invention;

Figures 7 and 8 are modifications of the stand structure of theapparatusof the present invention;

Figure 9 is an illustration of a modification of the leg structure ofthe present invention; and

Figure 10 is a top view of Figure 6.

Referring specifically to Figure 1 of the accompanying drawings, thereis provided a frame, generally designated by the reference numeral 1,comprising a first hollow, inverted U-shape member 2 and a secondhollow,

inverted U-shape member 3, spaced from and disposed parallel to thefirst. The U-shape frames 2 and 3 are interconnected by a bar 4 which issecured to and disposed perpendicularly of the frame members 2 and 3.Disposed within each of the hollow legs of the U-shape member 2 is atubular leg 6 which is vertically adjustbe readily adjusted in order toconform to the height of 2: ha -1. t s a ad la r-sen. the.

the child who is employing the structure.

Disposed between the legs of the U-shape member 2 is a hub 11 which issupported between the legsof the member 2 by means ofa plurality ofradially extending legs of the U-shape frame 3 and supportedtherebetween by a plurality of radially extending spokes or bars 14. Thehubs 11 and 13 are axially aligned and are adapted tosupportaaerank-shaft 1-6 of a crank generall-ydesig nated by thereference numeral 17 and havinga, crank handle 18.. {I'hecrank handle 18is gdisposed out-wa-rdly of the framemernher 3,.whi-le the crank shaft16 extends through the hub 11 and forwardly of the frame member 2. Anadjustable collar 19 is disposed about the crank shaft 16 and isnormally maintained in engagement with the hub 17 so as. to prevent endmotion of the crank shaft 16.

Rigidl-y secured to the shaft 16 adjacent the hub 11 g is a wheel 21which serves as a partial guide for two spiral springs 22 and 23. Thespiral springs. 22 and 23. are disposed about the shaft 16, andhave oneend 24 of the spring 23 as viewed in Figure 3 secured to the shaft 16.Theotherend of the spring 23, which'is designated (by the referencenumeral 26, is secured to a U-shaped retainer 27 .disposed on the shaft'4 while the corresponding end of the spiral spring '22 is secured to aU-shaped member 28 disposed on a surface of the bar 4. The ends of thespring areformed generally into loops 29 so that they curve about theU-shaped retaining members .and are thereby secured thereto. The springs,22 :and 23 are disposed n opposite sides of the wheel 21 in closeproximity thereto so that their adjacent edges are guided by the wheel;If necessary, wheels or cross members may be disposed on the othersides. of the springs 22 and 23 to provide further guide means therefor.The convolutions of the springs 22 and 23 are oppositely directed, sothat when one of the springs is wound the other spring is unwound.Winding of one of the springs and unwinding of the other is effected by,rotating the crank handle 18 in a given direction. When the handle isreleased the wound spring unwinds while the unwound spring winds until abalance of forces is effected, .at which time the spring which wasoriginally unwound winds, and vice versa. At this time the direction ofrotation of the shaft 16 is reversed and this process continues all ofthe initial energy stored in the originally wound springs is dissipated.

Secured to .the end of the .shaft 16 remote from the I crank handle 18is a hollow arm.. 31 which extends substantially at right angles to theshaft 16. The hollow arm 3'1 is adapted to support a rod 32 which isdisposed within the hollow arm 31 and is s'lidable with respect thereto.Therefore, the total length of the transverse arm may be adjusted andthe position of the arm 32 may be maintained by tightening athumb screw33. The arm 32 is provided with a weight 34 and terminates at itsend ina loop 36 to which a jump rope 37 may be tied. The purpose of theweighting of the arm 34 is two-fold. ;In a first instance, it serves toincrease the moment of inertia of the transverse arm to which the rope37 is attached, and therefore by adjusting the total length of the armcomprising the memberslfll and 32, therate at which the rope is rotatedmaybe controlled. The other put pose for the weight 34 is to reduce theangular velocity of the-rope on upward movement of the arms 3-l-32 Sincethe arms 3132 is weighted and therefore will produce a considerabledownward force while moving.

from its uppermost position to its lowermost position, the end the frame1 constitutingv the 'U-shape member '3 and legs 8 must beappropriatelyweighted to prevent the 4 legs 8 from being pulled oif the ground by thedownward thrust of the arm at the opposite end.

In a second embodiment of the present invention, illustrated in Figures6 and 10 of the accompanying drawings, a long flexible leaf spring 38 issecured to the wheel 21 and extends radially therefrom. The spring 38 ispositioned about the circumference of the wheel 21 such that it isdisposed immediately under the center bar 4 when the springs 22 and 23are at rest position A first horizontal stop pin 39 extends from one ofthe legs of the U-shape member 2 toward the U-shape member 3 asufficient distance to intercept the leaf .spring 38 when .it is rotatedsufficiently to come into the plane of the member 39. Similarly, ahorizontally extending stop member 41 extends from the other leg of theframe 2 toward the frame member '3 and is adapted to intercept thespring 38 upon its rotation into the plane of the member 41. In thisembodiment of the invention, the apparatus is intended to oscillate therope 37 through an:' angle .less than 360, and as illustrated in Figure6 less than 180. In operation the crank18 is rotated until the spring 38comes into contact with one of the stop members 39 and is ten sionedagainstthe stop. Upon releasing the crankhandle during whichoscillations may be sustained. 'Thesprings- 22 and 23 employed in thisembodiment, although identical in basic structure with those employed inthe first em bodiment of the invention, difler in their lengths, so

' they are appreciably tensioned by a rotation of the-shaft 16 throughonly 90", whereas 'those employed in the first embodiment, illustrated.in Figures 1 through 5, are appreciably tensioned only upon the. shaft16 being rotated through a large number of turns. The oscillations ofthe mechanism illustrated in Figure-.6 are sustained-only if the.natural frequency of the arms 31--32 is approximately equal to thenatural frequency of the spring .18 and also .of the springs 22 and 23,if employed. Referring: now to Figure 7 of .the accompanyingzdrawings,there is illustrated another species oftheframe which may be employed tosupport the: apparatusof the pres ent invention. provided with aninverted V-shaped 'member 42. -"I'-he inverted V-shape member 42includes hollow legs which are adapted to receive, internally thereof,extensible-legs increase the stability of the frame.

43 which may be secured in a predetermined position by thumb screws 44.The legs 43 in this embodiment-of the invention may terminate in flatdisc-like feet 46, to The frame is further provided with a horizontalcross member 47 which extends perpendicular .to the plane of the member42 and. is secured to. the apex thereof. The member 47 is secured at itsend remote from the frame 42 to a hollowvertical leg 48, which bisectsthe legs of the f-rame42. The. hollow leg 48 is adapted to receive afurther leg 49 in telescoping relationship therewith and the leg 49 maybe secured in .a given position by a thumb screw '51. The leg 49 alsoterminates in a fiat disc-like 52 to increase stability of mechanism. Afirst hub 53" for a crank shaft to be employed with the present ventionis disposed within the hollow leg 53, while aseo. 0nd hub 54 issupported on radial spokes 56 between tne. legs of .the V-shaped framemember 42.

Referring specifically to Figure .8 of the accompany. ing drawings,there-is illustrated another form of frame.

member Whichmay be ployed w th th spl f i the invention. The frameillustrated in Figure scam- In this figure one end of the frame is Theinverted V-shaped members 57 and 58 are of the frame. The invention isnot limited to any specific form of adjustable leg, and Figure 9illustrates another form of adjustable leg which may be employed. Theleg of the frame which is illustrated in Figure 9, and designated by thereference numeral 63, may be formed from a solid member and is providedwith two hollow U-shaped members 64 and 66 displaced axially along themember 63. An adjustable rod-like leg 67 is adapted to be inserted inthe hollow U-shaped members 64 and 66 and is held against the leg 63 bymeans of a thumb screw 68.

The apparatus of the present invention is intended to be employed bychildren and therefore some danger may arise from the fact that when oneof the springs, as 22 and 23, is under tension as a result of thewinding action provided by the crank handle 18, release of the handlewill generate rapid rotation thereof, and it may strike the operator. Inorder to eliminate this possibility, a suitable handle structure,illustrated in Figure 2, may be employed. Specifically, the handle 18 isconnected to the crank shaft 16 by means of a web member 69. The end ofthe web member 69 remote from the handle 18' terminates in a short stud71 disposed perpendicular to the member 69 and directed oppositely fromthe handle 18. The end of the stud 71 terminates a multi-sided element72, which is specifically illustrated as a foursided member, for thesake of example. The end of the shaft 16 adjacent the hub 13 has ahollow four-sided aperture 73 in which the multi-sided member 72 may beseated. The handle is supported on a rod 74 which extends into an axialrecess 76 in the rod 16. Disposed about the rod 74 is a spring, whichbiases the member 72 outwardly of the aperture 73 so that normally themember 72 does not engage the sides of the recess. As a result thehandle 18 may be rotated without rotating the shaft 16. When it isdesired to rotate the shaft 16 by the handle 18 the handle is pressedtoward the shaft 16 so that the multi-sided member 72 is seated in theaperture 73. The shaft 16 may then be rotated and when it is wished torelease the rod 16 the handle 18 is re leased, the spring 76 ejects themember 72 and the rod rotates without producing rotation of the handle.

While I have described and illustrated two specific embodiments of myinvention, it will be clear that variations of the details ofconstruction which are specifically illustrated and described may beresorted to without departing from the true spirit and scope of theinvention as defined in the appended claims.

What I claim is:

1. A mechanism for rotating a length of flexible material comprising arelatively long shaft, spaced bearings for rotatably supporting saidshaft in a generally horizontal position, a frame for supporting saidbearings, a pair of spiral springs disposed about said shaft with eachhaving one end secured to said shaft and the other end secured to saidframe, said spiral springs having their convolutions directed inopposite directions from one another, an arm secured to an end of saidshaft, said arm being disposed generally perpendicularly to said shaft,said arm being sufficiently heavy with respect to said springs to reducematerially the velocity of said arm upon upward movement thereof, and ahandle for initially rotating said shaft so as to wind one of saidsprings.

2. A mechanism for rotating a length of flexible material comprising arelatively long shaft, spaced bearings for rotatably supporting" saidshaft in a' generally horizontal position, a frame for supporting saidbearings, a source of rotary power'for rotatingsaidshaft, an secured isan end of said shaft, said beingl disposed generally perpendicular tosaid shaft, said arm being suficiently heavy with respect to the powercapability of'sai'd source of rotary power to, reduce materially the,velocity of said arm upon upward movement thereof. I, 3; Afmechanism.for rotating a length of flexible mar terial comprising a relatively.long shaft, spaced bearings for rotatably supporting said shaftiu'a'geneiallyhorizontal position, a frame for supporting said bearings,a pair of spiral springs disposed about said shaft with each having oneend secured to said shaft and the other end secured to said frame, saidspiral springs having their convolutions directed in opposite directionsfrom one another, an arm secured to an end of said shaft, said arm beingdisposed generally perpendicular to said shaft, said arm having a weightadjustably secured thereto, said weight being sufficiently heavy withrespect to said springs to reduce materially the velocity of said armupon upward movement thereof, a handle for initially rotating said shaftso as to wind one of said springs.

4. A mechanism for rotating a length of flexible material comprising arelatively long shaft, spaced bearings for rotatably supporting saidshaft in a generally horizontal position, a frame for supporting saidbearings, spring means having one end secured to said shaft and theother end engageable with said frame, a handle for rotating said shaftto displace said one end of said spring means relative to said other endthereby to'tension said spring means, an arm secured to an end of saidshaft, said arm being disposed generally perpendicular to said shaft,said arm being sufiiciently heavy withrespect to said springs to reducematerially the velocity of said arm upon upward movement thereof.

5. A mechanism for rotating a length of flexible material comprising arelatively long shaft, spaced bearings for rotatably supporting saidshaft in a generally horizontal position, a frame for supporting saidbearings, a flat spring having one end secured to said shaft and theother end free, a pair of stop members secured to said frame and eachpositioned to intercept said spring adjacent its free end, said stopsbeing disposed at predetermined spaced locations about the path ofmovement of the free end of said spring, an arm secured to an end ofsaid shaft, said arm being disposed generally perpendicular to saidshaft, said arm being sufiiciently heavy with respect to said springs toreduce materially the velocity of said arm upon upward movement thereof,and a handle for initially rotating said shaft so as to bring saidspring into contact with one of said stops and thereby tensioning saidspring.

6. The combination in accordance with claim 5, further comprising a pairof spiral springs disposed about said shaft, each spring having one endsecured to said shaft and the other end secured to said frame, saidspiral springs having their convolutions directed in opposite directionsto the other.

7. A mechanism for rotating a length of flexible material comp-rising arelatively long shaft, spaced bearings for rotatably supporting saidshaft in a generally horizontal position, a frame for supporting saidbearings, a pair of spiral springs disposed about said shaft with eachhaving one end secured to said shaft and the other end secured to saidframe, said spiral springs having their convolutions directed inopposite directions from one another, an arm secured to an end of saidshaft, said arm being disposed generally perpendicularly to said shaft,and a handle for initially rotating said shaft so as to wind one of saidsprings.

8. A mechanism for rotating a length of flexible material comprising arelatively long shaft, spaced bearings for rotatably supporting saidshaft in a generally horizontal a '7 r o position, ,a frame for.supporting s'a'id'bearings, a flat spring References Cited int-he fileof thisv patent having." one end secured to. said shaft. and the otherend UNITED STATES PATENTS free, a pair of st'op'menfl'aers secured tosaid frame and Y each positioned ,to' intercept said spring adjacent itsfree 5 3 Fomelius 8, 1935 end, said stops being, disposed atpredetermined spaced 5 $833,534 e May 6,1958 locations about the path ofmovement of the flee end FOREIGN PATENTS of said spring, an .arm'secured to an end of said shaft, said arm 'being disposed generallyperpendicular to said shaft, ,and .a handle for i'nitia'fly rotatingsaid shaft so as p a to'jbring saidfspring into contact with one of saidstops 0 and thereby tensioriing .said 'sprin g.

408,300 France Ian. 20, 1910

